Figure 4.

Inhibition of PrP-res formation in ScNB cells by meso-tetrasubstituted porphines (TSP). Analysis of effects of TSPs on PrP-res accumulation was performed as described in the legend to Fig. 1 and Materials and Methods. A superscript “a” indicates that no difference in PrP-res immunoblot signal intensity could be discerned visually between replicates; however, with the autoradiographic methodology used, it was difficult to discriminate differences of ≈±5%. A superscript “b” indicates that a >80% drop in the ³⁵S-PrP-res formation was observed between 10-fold dilutions of the inhibitor; we report the IC₅₀ as the concentration halfway between the 10-fold dilutions tested, but the actual value could be ≈±50% of that value.